package org.apache.maven.project;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.File;
import java.io.IOException;
import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

import javax.inject.Inject;
import javax.inject.Named;
import javax.inject.Singleton;

import org.apache.maven.RepositoryUtils;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.InvalidArtifactRTException;
import org.apache.maven.artifact.InvalidRepositoryException;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.artifact.repository.LegacyLocalRepositoryManager;
import org.apache.maven.bridge.MavenRepositorySystem;
import org.apache.maven.feature.Features;
import org.apache.maven.model.Build;
import org.apache.maven.model.Dependency;
import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.DeploymentRepository;
import org.apache.maven.model.Extension;
import org.apache.maven.model.Model;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.Profile;
import org.apache.maven.model.ReportPlugin;
import org.apache.maven.model.building.ArtifactModelSource;
import org.apache.maven.model.building.TransformerContextBuilder;
import org.apache.maven.model.building.DefaultModelBuildingRequest;
import org.apache.maven.model.building.DefaultModelProblem;
import org.apache.maven.model.building.FileModelSource;
import org.apache.maven.model.building.ModelBuilder;
import org.apache.maven.model.building.ModelBuildingException;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelBuildingResult;
import org.apache.maven.model.building.ModelProblem;
import org.apache.maven.model.building.ModelProcessor;
import org.apache.maven.model.building.ModelSource;
import org.apache.maven.model.building.StringModelSource;
import org.apache.maven.model.building.TransformerContext;
import org.apache.maven.model.resolution.ModelResolver;
import org.apache.maven.repository.internal.ArtifactDescriptorUtils;
import org.codehaus.plexus.logging.Logger;
import org.codehaus.plexus.util.Os;
import org.codehaus.plexus.util.StringUtils;
import org.eclipse.aether.RepositorySystemSession;
import org.eclipse.aether.RequestTrace;
import org.eclipse.aether.impl.RemoteRepositoryManager;
import org.eclipse.aether.repository.LocalRepositoryManager;
import org.eclipse.aether.repository.RemoteRepository;
import org.eclipse.aether.repository.WorkspaceRepository;
import org.eclipse.aether.resolution.ArtifactRequest;
import org.eclipse.aether.resolution.ArtifactResult;

/**
 * DefaultProjectBuilder
 */
@Named
@Singleton
public class DefaultProjectBuilder
    implements ProjectBuilder
{

    public static final String DISABLE_GLOBAL_MODEL_CACHE_SYSTEM_PROPERTY =
            "maven.defaultProjectBuilder.disableGlobalModelCache";

    @Inject
    private Logger logger;

    @Inject
    private ModelBuilder modelBuilder;

    @Inject
    private ModelProcessor modelProcessor;

    @Inject
    private ProjectBuildingHelper projectBuildingHelper;

    @Inject
    private MavenRepositorySystem repositorySystem;

    @Inject
    private org.eclipse.aether.RepositorySystem repoSystem;

    @Inject
    private RemoteRepositoryManager repositoryManager;

    @Inject
    private ProjectDependenciesResolver dependencyResolver;

    private final ReactorModelCache modelCache = new ReactorModelCache();

    // ----------------------------------------------------------------------
    // MavenProjectBuilder Implementation
    // ----------------------------------------------------------------------

    @Override
    public ProjectBuildingResult build( File pomFile, ProjectBuildingRequest request )
        throws ProjectBuildingException
    {
        return build( pomFile, new FileModelSource( pomFile ),
                new InternalConfig( request, null, useGlobalModelCache() ? getModelCache() : null, null ) );
    }

    private boolean useGlobalModelCache()
    {
        return !Boolean.getBoolean( DISABLE_GLOBAL_MODEL_CACHE_SYSTEM_PROPERTY );
    }

    @Override
    public ProjectBuildingResult build( ModelSource modelSource, ProjectBuildingRequest request )
        throws ProjectBuildingException
    {
        return build( null, modelSource,
                 new InternalConfig( request, null, useGlobalModelCache() ? getModelCache() : null, null ) );
    }

    private ProjectBuildingResult build( File pomFile, ModelSource modelSource, InternalConfig config )
        throws ProjectBuildingException
    {
        ClassLoader oldContextClassLoader = Thread.currentThread().getContextClassLoader();

        try
        {
            ProjectBuildingRequest projectBuildingRequest = config.request;

            MavenProject project = projectBuildingRequest.getProject();

            List<ModelProblem> modelProblems = null;
            Throwable error = null;

            if ( project == null )
            {
                ModelBuildingRequest request = getModelBuildingRequest( config );

                project = new MavenProject();
                project.setFile( pomFile );

                DefaultModelBuildingListener listener =
                    new DefaultModelBuildingListener( project, projectBuildingHelper, projectBuildingRequest );
                request.setModelBuildingListener( listener );

                request.setPomFile( pomFile );
                request.setModelSource( modelSource );
                request.setLocationTracking( true );

                ModelBuildingResult result;
                try
                {
                    result = modelBuilder.build( request );
                }
                catch ( ModelBuildingException e )
                {
                    result = e.getResult();
                    if ( result == null || result.getEffectiveModel() == null )
                    {
                        throw new ProjectBuildingException( e.getModelId(), e.getMessage(), pomFile, e );
                    }
                    // validation error, continue project building and delay failing to help IDEs
                    error = e;
                }

                modelProblems = result.getProblems();

                initProject( project, Collections.emptyMap(), true,
                             result, new HashMap<>(), projectBuildingRequest );
            }
            else if ( projectBuildingRequest.isResolveDependencies() )
            {
                projectBuildingHelper.selectProjectRealm( project );
            }

            DependencyResolutionResult resolutionResult = null;

            if ( projectBuildingRequest.isResolveDependencies() )
            {
                resolutionResult = resolveDependencies( project, config.session );
            }

            ProjectBuildingResult result = new DefaultProjectBuildingResult( project, modelProblems, resolutionResult );

            if ( error != null )
            {
                ProjectBuildingException e = new ProjectBuildingException( Arrays.asList( result ) );
                e.initCause( error );
                throw e;
            }

            return result;
        }
        finally
        {
            Thread.currentThread().setContextClassLoader( oldContextClassLoader );
        }
    }

    private DependencyResolutionResult resolveDependencies( MavenProject project, RepositorySystemSession session )
    {
        DependencyResolutionResult resolutionResult;

        try
        {
            DefaultDependencyResolutionRequest resolution = new DefaultDependencyResolutionRequest( project, session );
            resolutionResult = dependencyResolver.resolve( resolution );
        }
        catch ( DependencyResolutionException e )
        {
            resolutionResult = e.getResult();
        }

        Set<Artifact> artifacts = new LinkedHashSet<>();
        if ( resolutionResult.getDependencyGraph() != null )
        {
            RepositoryUtils.toArtifacts( artifacts, resolutionResult.getDependencyGraph().getChildren(),
                                         Collections.singletonList( project.getArtifact().getId() ), null );

            // Maven 2.x quirk: an artifact always points at the local repo, regardless whether resolved or not
            LocalRepositoryManager lrm = session.getLocalRepositoryManager();
            for ( Artifact artifact : artifacts )
            {
                if ( !artifact.isResolved() )
                {
                    String path = lrm.getPathForLocalArtifact( RepositoryUtils.toArtifact( artifact ) );
                    artifact.setFile( new File( lrm.getRepository().getBasedir(), path ) );
                }
            }
        }
        project.setResolvedArtifacts( artifacts );
        project.setArtifacts( artifacts );

        return resolutionResult;
    }

    private List<String> getProfileIds( List<Profile> profiles )
    {
        return profiles.stream().map( Profile::getId ).collect( Collectors.toList() );
    }

    private ModelBuildingRequest getModelBuildingRequest( InternalConfig config )
    {
        ProjectBuildingRequest configuration = config.request;

        ModelBuildingRequest request = new DefaultModelBuildingRequest();

        RequestTrace trace = RequestTrace.newChild( null, configuration ).newChild( request );

        ModelResolver resolver =
            new ProjectModelResolver( config.session, trace, repoSystem, repositoryManager, config.repositories,
                                      configuration.getRepositoryMerging(), config.modelPool );

        request.setValidationLevel( configuration.getValidationLevel() );
        request.setProcessPlugins( configuration.isProcessPlugins() );
        request.setProfiles( configuration.getProfiles() );
        request.setActiveProfileIds( configuration.getActiveProfileIds() );
        request.setInactiveProfileIds( configuration.getInactiveProfileIds() );
        request.setSystemProperties( configuration.getSystemProperties() );
        request.setUserProperties( configuration.getUserProperties() );
        request.setBuildStartTime( configuration.getBuildStartTime() );
        request.setModelResolver( resolver );
        request.setModelCache( config.modelCache );
        request.setTransformerContextBuilder( config.transformerContextBuilder );

        return request;
    }

    @Override
    public ProjectBuildingResult build( Artifact artifact, ProjectBuildingRequest request )
        throws ProjectBuildingException
    {
        return build( artifact, false, request );
    }

    @Override
    public ProjectBuildingResult build( Artifact artifact, boolean allowStubModel, ProjectBuildingRequest request )
        throws ProjectBuildingException
    {
        org.eclipse.aether.artifact.Artifact pomArtifact = RepositoryUtils.toArtifact( artifact );
        pomArtifact = ArtifactDescriptorUtils.toPomArtifact( pomArtifact );

        InternalConfig config =
            new InternalConfig( request, null, useGlobalModelCache() ? getModelCache() : null, null );

        boolean localProject;

        try
        {
            ArtifactRequest pomRequest = new ArtifactRequest();
            pomRequest.setArtifact( pomArtifact );
            pomRequest.setRepositories( config.repositories );
            ArtifactResult pomResult = repoSystem.resolveArtifact( config.session, pomRequest );

            pomArtifact = pomResult.getArtifact();
            localProject = pomResult.getRepository() instanceof WorkspaceRepository;
        }
        catch ( org.eclipse.aether.resolution.ArtifactResolutionException e )
        {
            if ( e.getResults().get( 0 ).isMissing() && allowStubModel )
            {
                return build( null, createStubModelSource( artifact ), config );
            }
            throw new ProjectBuildingException( artifact.getId(),
                                                "Error resolving project artifact: " + e.getMessage(), e );
        }

        File pomFile = pomArtifact.getFile();

        if ( "pom".equals( artifact.getType() ) )
        {
            artifact.selectVersion( pomArtifact.getVersion() );
            artifact.setFile( pomFile );
            artifact.setResolved( true );
        }

        if ( localProject )
        {
            return build( pomFile, new FileModelSource( pomFile ), config );
        }
        else
        {
            return build( null, new ArtifactModelSource( pomFile, artifact.getGroupId(), artifact.getArtifactId(),
                                                         artifact.getVersion() ),
                          config );
        }
    }

    private ModelSource createStubModelSource( Artifact artifact )
    {
        StringBuilder buffer = new StringBuilder( 1024 );

        buffer.append( "<?xml version='1.0'?>" );
        buffer.append( "<project>" );
        buffer.append( "<modelVersion>4.0.0</modelVersion>" );
        buffer.append( "<groupId>" ).append( artifact.getGroupId() ).append( "</groupId>" );
        buffer.append( "<artifactId>" ).append( artifact.getArtifactId() ).append( "</artifactId>" );
        buffer.append( "<version>" ).append( artifact.getBaseVersion() ).append( "</version>" );
        buffer.append( "<packaging>" ).append( artifact.getType() ).append( "</packaging>" );
        buffer.append( "</project>" );

        return new StringModelSource( buffer, artifact.getId() );
    }

    @Override
    public List<ProjectBuildingResult> build( List<File> pomFiles, boolean recursive, ProjectBuildingRequest request )
        throws ProjectBuildingException
    {
        List<ProjectBuildingResult> results = new ArrayList<>();

        List<InterimResult> interimResults = new ArrayList<>();

        ReactorModelPool.Builder poolBuilder = new ReactorModelPool.Builder();
        final ReactorModelPool modelPool = poolBuilder.build();

        InternalConfig config =
            new InternalConfig( request, modelPool, useGlobalModelCache() ? getModelCache() : new ReactorModelCache(),
                        modelBuilder.newTransformerContextBuilder() );

        Map<File, MavenProject> projectIndex = new HashMap<>( 256 );

        // phase 1: get file Models from the reactor.
        boolean noErrors =
            build( results, interimResults, projectIndex, pomFiles, new LinkedHashSet<>(), true, recursive,
                   config, poolBuilder );

        ClassLoader oldContextClassLoader = Thread.currentThread().getContextClassLoader();

        try
        {
            // Phase 2: get effective models from the reactor
            noErrors =
                build( results, new ArrayList<>(), projectIndex, interimResults, request,
                        new HashMap<>(), config.session ) && noErrors;
        }
        finally
        {
            Thread.currentThread().setContextClassLoader( oldContextClassLoader );
        }

        if ( Features.buildConsumer().isActive() )
        {
            request.getRepositorySession().getData().set( TransformerContext.KEY,
                                                          config.transformerContextBuilder.build() );
        }

        if ( !noErrors )
        {
            throw new ProjectBuildingException( results );
        }

        return results;
    }

    @SuppressWarnings( "checkstyle:parameternumber" )
    private boolean build( List<ProjectBuildingResult> results, List<InterimResult> interimResults,
                           Map<File, MavenProject> projectIndex, List<File> pomFiles, Set<File> aggregatorFiles,
                           boolean root, boolean recursive, InternalConfig config,
                           ReactorModelPool.Builder poolBuilder )
    {
        boolean noErrors = true;

        for ( File pomFile : pomFiles )
        {
            aggregatorFiles.add( pomFile );

            if ( !build( results, interimResults, projectIndex, pomFile, aggregatorFiles, root, recursive, config,
                         poolBuilder ) )
            {
                noErrors = false;
            }

            aggregatorFiles.remove( pomFile );
        }

        return noErrors;
    }

    @SuppressWarnings( "checkstyle:parameternumber" )
    private boolean build( List<ProjectBuildingResult> results, List<InterimResult> interimResults,
                           Map<File, MavenProject> projectIndex, File pomFile, Set<File> aggregatorFiles,
                           boolean isRoot, boolean recursive, InternalConfig config,
                           ReactorModelPool.Builder poolBuilder )
    {
        boolean noErrors = true;

        MavenProject project = new MavenProject();
        project.setFile( pomFile );

        ModelBuildingRequest request = getModelBuildingRequest( config )
                        .setPomFile( pomFile )
                        .setTwoPhaseBuilding( true )
                        .setLocationTracking( true );

        DefaultModelBuildingListener listener =
            new DefaultModelBuildingListener( project, projectBuildingHelper, config.request );
        request.setModelBuildingListener( listener );

        ModelBuildingResult result;
        try
        {
            result = modelBuilder.build( request );
        }
        catch ( ModelBuildingException e )
        {
            result = e.getResult();
            if ( result == null || result.getFileModel() == null )
            {
                 results.add( new DefaultProjectBuildingResult( e.getModelId(), pomFile, e.getProblems() ) );

                 return false;
            }
            // validation error, continue project building and delay failing to help IDEs
            // result.getProblems().addAll(e.getProblems()) ?
            noErrors = false;
        }

        Model model = result.getFileModel().clone();

        poolBuilder.put( model.getPomFile().toPath(),  model );

        InterimResult interimResult = new InterimResult( pomFile, request, result, listener, isRoot );
        interimResults.add( interimResult );

        if ( recursive )
        {
            File basedir = pomFile.getParentFile();
            List<File> moduleFiles = new ArrayList<>();
            for ( String module : model.getModules() )
            {
                if ( StringUtils.isEmpty( module ) )
                {
                    continue;
                }

                module = module.replace( '\\', File.separatorChar ).replace( '/', File.separatorChar );

                File moduleFile = new File( basedir, module );

                if ( moduleFile.isDirectory() )
                {
                    moduleFile = modelProcessor.locatePom( moduleFile );
                }

                if ( !moduleFile.isFile() )
                {
                    ModelProblem problem =
                        new DefaultModelProblem( "Child module " + moduleFile + " of " + pomFile
                            + " does not exist", ModelProblem.Severity.ERROR, ModelProblem.Version.BASE, model, -1,
                                                 -1, null );
                    result.getProblems().add( problem );

                    noErrors = false;

                    continue;
                }

                if ( Os.isFamily( Os.FAMILY_WINDOWS ) )
                {
                    // we don't canonicalize on unix to avoid interfering with symlinks
                    try
                    {
                        moduleFile = moduleFile.getCanonicalFile();
                    }
                    catch ( IOException e )
                    {
                        moduleFile = moduleFile.getAbsoluteFile();
                    }
                }
                else
                {
                    moduleFile = new File( moduleFile.toURI().normalize() );
                }

                if ( aggregatorFiles.contains( moduleFile ) )
                {
                    StringBuilder buffer = new StringBuilder( 256 );
                    for ( File aggregatorFile : aggregatorFiles )
                    {
                        buffer.append( aggregatorFile ).append( " -> " );
                    }
                    buffer.append( moduleFile );

                    ModelProblem problem =
                        new DefaultModelProblem( "Child module " + moduleFile + " of " + pomFile
                            + " forms aggregation cycle " + buffer, ModelProblem.Severity.ERROR,
                                                 ModelProblem.Version.BASE, model, -1, -1, null );
                    result.getProblems().add( problem );

                    noErrors = false;

                    continue;
                }

                moduleFiles.add( moduleFile );
            }

            interimResult.modules = new ArrayList<>();

            if ( !build( results, interimResult.modules, projectIndex, moduleFiles, aggregatorFiles, false,
                         recursive, config, poolBuilder ) )
            {
                noErrors = false;
            }
        }

        projectIndex.put( pomFile, project );

        return noErrors;
    }

    static class InterimResult
    {

        File pomFile;

        ModelBuildingRequest request;

        ModelBuildingResult result;

        DefaultModelBuildingListener listener;

        boolean root;

        List<InterimResult> modules = Collections.emptyList();

        InterimResult( File pomFile, ModelBuildingRequest request, ModelBuildingResult result,
                       DefaultModelBuildingListener listener, boolean root )
        {
            this.pomFile = pomFile;
            this.request = request;
            this.result = result;
            this.listener = listener;
            this.root = root;
        }

    }

    private boolean build( List<ProjectBuildingResult> results, List<MavenProject> projects,
                           Map<File, MavenProject> projectIndex, List<InterimResult> interimResults,
                           ProjectBuildingRequest request, Map<File, Boolean> profilesXmls,
                           RepositorySystemSession session )
    {
        boolean noErrors = true;

        for ( InterimResult interimResult : interimResults )
        {
            MavenProject project = interimResult.listener.getProject();
            try
            {
                ModelBuildingResult result = modelBuilder.build( interimResult.request, interimResult.result );

                // 2nd pass of initialization: resolve and build parent if necessary
                try
                {
                    initProject( project, projectIndex, true, result, profilesXmls, request );
                }
                catch ( InvalidArtifactRTException iarte )
                {
                    result.getProblems().add( new DefaultModelProblem( null, ModelProblem.Severity.ERROR, null,
                            result.getEffectiveModel(), -1, -1, iarte ) );
                }

                List<MavenProject> modules = new ArrayList<>();
                noErrors =
                    build( results, modules, projectIndex, interimResult.modules, request, profilesXmls, session )
                    && noErrors;

                projects.addAll( modules );
                projects.add( project );

                project.setExecutionRoot( interimResult.root );
                project.setCollectedProjects( modules );
                DependencyResolutionResult resolutionResult = null;
                if ( request.isResolveDependencies() )
                {
                    resolutionResult = resolveDependencies( project, session );
                }

                results.add( new DefaultProjectBuildingResult( project, result.getProblems(), resolutionResult ) );
            }
            catch ( ModelBuildingException e )
            {
                DefaultProjectBuildingResult result = null;
                if ( project == null || interimResult.result.getEffectiveModel() == null )
                {
                    result = new DefaultProjectBuildingResult( e.getModelId(), interimResult.pomFile, e.getProblems() );
                }
                else
                {
                    project.setModel( interimResult.result.getEffectiveModel() );

                    result = new DefaultProjectBuildingResult( project, e.getProblems(), null );
                }
                results.add( result );

                noErrors = false;
            }
        }

        return noErrors;
    }

    @SuppressWarnings( "checkstyle:methodlength" )
    private void initProject( MavenProject project, Map<File, MavenProject> projects,
                              boolean buildParentIfNotExisting, ModelBuildingResult result,
                              Map<File, Boolean> profilesXmls, ProjectBuildingRequest projectBuildingRequest )
    {
        Model model = result.getEffectiveModel();

        project.setModel( model );
        project.setOriginalModel( result.getFileModel() );

        initParent( project, projects, buildParentIfNotExisting, result, projectBuildingRequest );

        Artifact projectArtifact =
            repositorySystem.createArtifact( project.getGroupId(), project.getArtifactId(), project.getVersion(), null,
                                             project.getPackaging() );
        project.setArtifact( projectArtifact );

        if ( project.getFile() != null && buildParentIfNotExisting ) // only set those on 2nd phase, ignore on 1st pass
        {
            Build build = project.getBuild();
            project.addScriptSourceRoot( build.getScriptSourceDirectory() );
            project.addCompileSourceRoot( build.getSourceDirectory() );
            project.addTestCompileSourceRoot( build.getTestSourceDirectory() );
        }

        List<Profile> activeProfiles = new ArrayList<>();
        activeProfiles.addAll( result.getActivePomProfiles( result.getModelIds().get( 0 ) ) );
        activeProfiles.addAll( result.getActiveExternalProfiles() );
        project.setActiveProfiles( activeProfiles );

        project.setInjectedProfileIds( "external", getProfileIds( result.getActiveExternalProfiles() ) );
        for ( String modelId : result.getModelIds() )
        {
            project.setInjectedProfileIds( modelId, getProfileIds( result.getActivePomProfiles( modelId ) ) );
        }

        String modelId = findProfilesXml( result, profilesXmls );
        if ( modelId != null )
        {
            ModelProblem problem =
                new DefaultModelProblem( "Detected profiles.xml alongside " + modelId
                    + ", this file is no longer supported and was ignored" + ", please use the settings.xml instead",
                                         ModelProblem.Severity.WARNING, ModelProblem.Version.V30, model, -1, -1, null );
            result.getProblems().add( problem );
        }

        //
        // All the parts that were taken out of MavenProject for Maven 4.0.0
        //

        project.setProjectBuildingRequest( projectBuildingRequest );

        // pluginArtifacts
        Set<Artifact> pluginArtifacts = new HashSet<>();
        for ( Plugin plugin : project.getBuildPlugins() )
        {
            Artifact artifact = repositorySystem.createPluginArtifact( plugin );

            if ( artifact != null )
            {
                pluginArtifacts.add( artifact );
            }
        }
        project.setPluginArtifacts( pluginArtifacts );

        // reportArtifacts
        Set<Artifact> reportArtifacts = new HashSet<>();
        for ( ReportPlugin report : project.getReportPlugins() )
        {
            Plugin pp = new Plugin();
            pp.setGroupId( report.getGroupId() );
            pp.setArtifactId( report.getArtifactId() );
            pp.setVersion( report.getVersion() );

            Artifact artifact = repositorySystem.createPluginArtifact( pp );

            if ( artifact != null )
            {
                reportArtifacts.add( artifact );
            }
        }
        project.setReportArtifacts( reportArtifacts );

        // extensionArtifacts
        Set<Artifact> extensionArtifacts = new HashSet<>();
        List<Extension> extensions = project.getBuildExtensions();
        if ( extensions != null )
        {
            for ( Extension ext : extensions )
            {
                String version;
                if ( StringUtils.isEmpty( ext.getVersion() ) )
                {
                    version = "RELEASE";
                }
                else
                {
                    version = ext.getVersion();
                }

                Artifact artifact =
                    repositorySystem.createArtifact( ext.getGroupId(), ext.getArtifactId(), version, null, "jar" );

                if ( artifact != null )
                {
                    extensionArtifacts.add( artifact );
                }
            }
        }
        project.setExtensionArtifacts( extensionArtifacts );

        // managedVersionMap
        Map<String, Artifact> map = null;
        if ( repositorySystem != null )
        {
            final DependencyManagement dependencyManagement = project.getDependencyManagement();
            if ( ( dependencyManagement != null ) && ( ( dependencyManagement.getDependencies() ) != null )
                && ( dependencyManagement.getDependencies().size() > 0 ) )
            {
                map = new AbstractMap<String, Artifact>()
                {
                    HashMap<String, Artifact> delegate;

                    @Override
                    public Set<Entry<String, Artifact>> entrySet()
                    {
                        return Collections.unmodifiableSet( compute().entrySet() );
                    }

                    @Override
                    public Set<String> keySet()
                    {
                        return Collections.unmodifiableSet( compute().keySet() );
                    }

                    @Override
                    public Collection<Artifact> values()
                    {
                        return Collections.unmodifiableCollection( compute().values() );
                    }

                    @Override
                    public boolean containsValue( Object value )
                    {
                        return compute().containsValue( value );
                    }

                    @Override
                    public boolean containsKey( Object key )
                    {
                        return compute().containsKey( key );
                    }

                    @Override
                    public Artifact get( Object key )
                    {
                        return compute().get( key );
                    }

                    HashMap<String, Artifact> compute()
                    {
                        if ( delegate == null )
                        {
                            delegate = new HashMap<>();
                            for ( Dependency d : dependencyManagement.getDependencies() )
                            {
                                Artifact artifact = repositorySystem.createDependencyArtifact( d );

                                if ( artifact != null )
                                {
                                    delegate.put( d.getManagementKey(), artifact );
                                }
                            }
                        }

                        return delegate;
                    }
                };
            }
            else
            {
                map = Collections.emptyMap();
            }
        }
        project.setManagedVersionMap( map );

        // release artifact repository
        if ( project.getDistributionManagement() != null
                        && project.getDistributionManagement().getRepository() != null )
        {
            try
            {
                DeploymentRepository r = project.getDistributionManagement().getRepository();
                if ( !StringUtils.isEmpty( r.getId() ) && !StringUtils.isEmpty( r.getUrl() ) )
                {
                    ArtifactRepository repo = MavenRepositorySystem.buildArtifactRepository( r );
                    repositorySystem.injectProxy( projectBuildingRequest.getRepositorySession(),
                                                  Arrays.asList( repo ) );
                    repositorySystem.injectAuthentication( projectBuildingRequest.getRepositorySession(),
                                                           Arrays.asList( repo ) );
                    project.setReleaseArtifactRepository( repo );
                }
            }
            catch ( InvalidRepositoryException e )
            {
                throw new IllegalStateException( "Failed to create release distribution repository for "
                    + project.getId(), e );
            }
        }

        // snapshot artifact repository
        if ( project.getDistributionManagement() != null
            && project.getDistributionManagement().getSnapshotRepository() != null )
        {
            try
            {
                DeploymentRepository r = project.getDistributionManagement().getSnapshotRepository();
                if ( !StringUtils.isEmpty( r.getId() ) && !StringUtils.isEmpty( r.getUrl() ) )
                {
                    ArtifactRepository repo = MavenRepositorySystem.buildArtifactRepository( r );
                    repositorySystem.injectProxy( projectBuildingRequest.getRepositorySession(),
                                                  Arrays.asList( repo ) );
                    repositorySystem.injectAuthentication( projectBuildingRequest.getRepositorySession(),
                                                           Arrays.asList( repo ) );
                    project.setSnapshotArtifactRepository( repo );
                }
            }
            catch ( InvalidRepositoryException e )
            {
                throw new IllegalStateException( "Failed to create snapshot distribution repository for "
                    + project.getId(), e );
            }
        }
    }

    private void initParent( MavenProject project, Map<File, MavenProject> projects, boolean buildParentIfNotExisting,
                             ModelBuildingResult result, ProjectBuildingRequest projectBuildingRequest )
    {
        Model parentModel = result.getModelIds().size() > 1 && !result.getModelIds().get( 1 ).isEmpty()
                                ? result.getRawModel( result.getModelIds().get( 1 ) )
                                : null;

        if ( parentModel != null )
        {
            final String parentGroupId = inheritedGroupId( result, 1 );
            final String parentVersion = inheritedVersion( result, 1 );

            project.setParentArtifact( repositorySystem.createProjectArtifact( parentGroupId,
                                                                               parentModel.getArtifactId(),
                                                                               parentVersion ) );

            // org.apache.maven.its.mng4834:parent:0.1
            String parentModelId = result.getModelIds().get( 1 );
            File parentPomFile = result.getRawModel( parentModelId ).getPomFile();
            MavenProject parent = projects.get( parentPomFile );
            if ( parent == null && buildParentIfNotExisting )
            {
                //
                // At this point the DefaultModelBuildingListener has fired and it populates the
                // remote repositories with those found in the pom.xml, along with the existing externally
                // defined repositories.
                //
                projectBuildingRequest.setRemoteRepositories( project.getRemoteArtifactRepositories() );
                if ( parentPomFile != null )
                {
                    project.setParentFile( parentPomFile );
                    try
                    {
                        parent = build( parentPomFile, projectBuildingRequest ).getProject();
                    }
                    catch ( ProjectBuildingException e )
                    {
                        // MNG-4488 where let invalid parents slide on by
                        if ( logger.isDebugEnabled() )
                        {
                            // Message below is checked for in the MNG-2199 core IT.
                            logger.warn( "Failed to build parent project for " + project.getId(), e );
                        }
                        else
                        {
                            // Message below is checked for in the MNG-2199 core IT.
                            logger.warn( "Failed to build parent project for " + project.getId() );
                        }
                    }
                }
                else
                {
                    Artifact parentArtifact = project.getParentArtifact();
                    try
                    {
                        parent = build( parentArtifact, projectBuildingRequest ).getProject();
                    }
                    catch ( ProjectBuildingException e )
                    {
                        // MNG-4488 where let invalid parents slide on by
                        if ( logger.isDebugEnabled() )
                        {
                            // Message below is checked for in the MNG-2199 core IT.
                            logger.warn( "Failed to build parent project for " + project.getId(), e );
                        }
                        else
                        {
                            // Message below is checked for in the MNG-2199 core IT.
                            logger.warn( "Failed to build parent project for " + project.getId() );
                        }
                    }
                }
            }
            project.setParent( parent );
            if ( project.getParentFile() == null && parent != null )
            {
                project.setParentFile( parent.getFile() );
            }
        }
    }

    private static String inheritedGroupId( final ModelBuildingResult result, final int modelIndex )
    {
        String groupId = null;
        final String modelId = result.getModelIds().get( modelIndex );

        if ( !modelId.isEmpty() )
        {
            final Model model = result.getRawModel( modelId );
            groupId = model.getGroupId() != null
                          ? model.getGroupId()
                          : inheritedGroupId( result, modelIndex + 1 );

        }

        return groupId;
    }

    private static String inheritedVersion( final ModelBuildingResult result, final int modelIndex )
    {
        String version = null;
        final String modelId = result.getModelIds().get( modelIndex );

        if ( !modelId.isEmpty() )
        {
            final Model model = result.getRawModel( modelId );
            version = model.getVersion() != null
                          ? model.getVersion()
                          : inheritedVersion( result, modelIndex + 1 );

        }

        return version;
    }

    private String findProfilesXml( ModelBuildingResult result, Map<File, Boolean> profilesXmls )
    {
        for ( String modelId : result.getModelIds() )
        {
            Model model = result.getRawModel( modelId );

            File basedir = model.getProjectDirectory();
            if ( basedir == null )
            {
                break;
            }

            Boolean profilesXml = profilesXmls.get( basedir );
            if ( profilesXml == null )
            {
                profilesXml = new File( basedir, "profiles.xml" ).exists();
                profilesXmls.put( basedir, profilesXml );
            }
            if ( profilesXml )
            {
                return modelId;
            }
        }

        return null;
    }

    /**
     * InternalConfig
     */
    class InternalConfig
    {

        private final ProjectBuildingRequest request;

        private final RepositorySystemSession session;

        private final List<RemoteRepository> repositories;

        private final ReactorModelPool modelPool;

        private final ReactorModelCache modelCache;

        private final TransformerContextBuilder transformerContextBuilder;

        InternalConfig( ProjectBuildingRequest request, ReactorModelPool modelPool, ReactorModelCache modelCache,
                        TransformerContextBuilder transformerContextBuilder )
        {
            this.request = request;
            this.modelPool = modelPool;
            this.modelCache = modelCache;
            this.transformerContextBuilder = transformerContextBuilder;

            session =
                LegacyLocalRepositoryManager.overlay( request.getLocalRepository(), request.getRepositorySession(),
                                                      repoSystem );
            repositories = RepositoryUtils.toRepos( request.getRemoteRepositories() );

        }

    }

    private ReactorModelCache getModelCache()
    {
        return this.modelCache;
    }

}